At the present time, the calorimetric setting of each display unit is done manually. It has been shown that this solution is not completely satisfactory, particularly due to the fact that the precision obtained by manual settings is not enough to eliminate all perceptible differences in the colorimetric rendering between two adjacent screens. Since the operator's eye is the only measurement instrument used, the evaluation of differences in calorimetric rendering remains very subjective.
Tools are available for observing and measuring display surfaces, such as calorimetric probes. However, this type of tool has never been combined with display unit adjustment systems or video processing systems.
Moreover, the operator remains dependent on the limits of the capacity to adjust the different video systems (no very large adjustment increment, adjustment inertia). All these limitations mean that manual adjustments are very approximate.
Moreover, regardless of the display technique used, the calorimetric rendering of a screen is subject to slow variations, particularly due to aging of some display unit or video system devices, which means that such adjustments have to be made regularly. Since these adjustments require a visit by an operator, it often happens that they are not carried out when they are necessary.